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Flashcards in Enzyme interactions Deck (18)
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1

What is a cofactor?

A substance not made from amino acids but required by an enzyme to function

2

What two types of cofactors are there?

Permanent part of molecule (prosthetic group) or a temporary part

3

What is an inorganic cofactor?

Inorganic ions needed by an enzyme to function (e.g. zinc)

4

What do inorganic ions do?

Either help stabilize the enzyme structure, or take part in the reaction at the AS

5

What is a coenzyme?

Small inorganic, non protein cofactor

6

What do coenzymes do?

Help in catalysing reactions, donating or accepting hydrogen ions or phosphate groups

7

How do coenzymes attach to the enzyme?

can bind permanently near or on AS, or bind temporarily to AS

8

What is an inhibitor?

Any substance that slows or stops an enzyme catalysed reaction

9

What is non-reversible inhibition?

When the inhibitor combines permanently with an enzyme, completely inactivating it

10

What must the cell do when an enzyme is under non-reversible inhibition?

Cell must produce more of the enzyme through activating the gene(s) so that they are transcribed and translated

11

What is reversible inhibition?

Occurs when inhibitor combines temporarily with an enzyme, can be revered and enzyme activated again

12

What are the two types of reversible inhibitors?

Competitive, non-competitive

13

What is competitive inhibition?

Occurs when an inhibitor with same shape as the substrate combines with AS, blocking access for substrate (competes with substrate)

14

How can competitive inhibition be reversed?

Increase the concentration of substrate

15

What is non-competitive inhibition?

Occurs when an inhibitor combines with the allosteric site on an enzyme, changing the tertiary structure so that the AS is no longer complementary to the substrate

16

Is non-competitive inhibition reversible?

No, once all allosteric sites are inhibited increasing the substrate concentration will have no effect on the ROR

17

What do inhibitors act as?

Can be poisonous or act as medicinal drugs

18

Benefit of inhibitor penicillin?

Bacteria are destroyed, non-reversible inhibition of the enzyme responsible for forming cross links in bacterial cell walls